Lockout mechanism for lock sets



March 24, 1964 A. KUCHLER 3,125,876

LOCKOUT MECHANISM FOR LOCK SETS Filed April 6, 1960 2 Sheets-Sheet 1 INVENTOR. ABRAHAM KUCHL ER BY i ATTORNEY March 24, 1964 KUCHLER 3,125,876

LOCKOUT MECHANISM FOR LOCK SETS Filed April 6. 1960 2 Sheets-Sheet 2 77 v I I I I I INVENTOR. J 1/ ABRAHAM KucHL ER Arron/5r United States Patent 3,125,876 LOtZKfiUT MECHAWESM FOR LGQK SETS Abraham Knchler, Anaheim, Calif., assignor to The American Hardware Corporation, New Britain, tlornn, a corporation of Connecticut Filed Apr. 6, 196% Ser. No. 20,374 7 Claims. (Cl. 70-146) This invention relates to a lockout mechanism for lock sets.

The lockout mechanism of the invention is particularly applicable in lock sets which are applied to the doors of hotel rooms and the like, and is characterized by the fact that it will permit a guest to inactivate the lock set while he is in the room so that he will not be disturbed. Moreover, the lockout mechanism permits the lock set and, more particularly, the lock associated with said lock set, to be blocked by the management of the hotel or motel to prevent a guest from having access to the room by the use of the ordinary lock key.

It is, therefore, an object of the invention to provide a lockout mechanism of the aforementioned character which is characterized by the provision of first dogging means adapted to maintain the associated lockout mechanism for the lock of the lock set in operative condition when the guest occupying the room activates the lockout means to prevent access to the room by the use of an ordinary key.

Another object of the invention is the provision of a second dogging means adapted to be energized by a special key, whereby the management of the hotel or motel may activate the lockout means to prevent a guest from having access to the room he formerly occupied by the use of an ordinary key.

A further object of the invention is the provision of lockout means of the aforementioned character wherein the first dogging means is automatically rendered inoperative when a guest opens the door in which the lock set is located to leave the room and wherein the second dogging means is maintained in operative condition despite the opening of the door with which the lock set is associated. Therefore, the management can inactivate the lock of the lock set, open and close t e door, and the lockout means will still remain in operative condition. However, if a guest, having blocked the lock of the lock set should leave the room, retraction of the bolt of the lock set will automatically release the blocking means. Therefore, a guest can not render the lock set inoperative after he has opened the door and left the room.

Another object of the invention is the provision of a lock set incorporating lockout means of the aforementioned character, wherein the lockout mechanism can be overridden by a master emergency key in the possession of management so that management of a hotel or motel can enter a room in which the lock set has been rendered inoperative by a guest or when the lock set has been rendered inoperative by management itself.

Other objects and advantages of the invention will be apparent from the following specification and the accompanying drawings, which are for the purpose of illustration only, and in which:

FIG. 1 is a perspective View showing a typical installation of a lock set incorporating the lookout means of the invention;

FIG. 2 is a transverse sectional view taken on the broken line 2-2 of FIG. 1;

FIG. 3 is a longitudinal sectional view taken on the broken line 3-3 of FIG. 2;

FIG. 4 is a transverse sectional view taken on the broken line i i of FIG. 2;

FIG. 5 is a transverse sectional view similar to FIG. 2

"ice

but showing the manner in which the lookout mechanism may be dogged by the use of the second dogging means;

PEG. 6 is a transverse sectional view taken on the broken line 6-6 of FIG. 5;

FIG. 7 is an enlarged, fragmentary view of a portion of the dogging mechanism of the lookout means;

FIG. 8 is a side elevational view of a typical conventional key adapted to be utilized in the lock of the lock set incorporating the lockout mechanism;

FIG. 9 is an enlarged fragmentary, side elevational view of the master emergency key;

FIG. 10 is a vertical sectional view taken on the broken line lit-dd of FIG. 9; and

FIG. 11 is a longitudinal sectional view showing the manner in which the lookout mechanism is maintained in inoperative condition when actuated by a guest.

In reference to the drawings, and particularly to FIGS. l2 thereof, I show a lock set iii mounted on a door 12 of a hotel room or the like and including an interior knob 14 and an exterior knob 16, said interior and exterior knobs being accessible, respectively, from the interior and exterior of the door 12. The lock set includes a bolt 13 adapted to engage a corresponding strike, not shown, in the jamb of the door opening, said bolt having a dogging blade Ztl associated therewith and being mounted for movement in the latch case 22.

The belt 18 is, as best shown in FIG. 3 of the dra ings, provided with an integral bolt extension 24 having an engagement slot 26 therein. Associated with the bolt extension 24 is a slide 28 having its rearward extremity providing spindle engaging surfaces thereupon, for a purpose which will be described in greater detail below.

A pivot pin 32 extends through the latch case 22 and has a retractor cam 34 mounted thereupon with its lower extremity 36 disposed in the engagement slot 26 while its upper extremity is adapted to be engaged by the slide 28 to cause counterclockwise rotation of said cam to with draw the bolt is into the latch case 22. The dogging blade 2d is normally biased outwardly from the associated end of the slide 28 by a compression spring 38. The dogging blade 24) has an extension 40 mounted in a slot 42 in the slide 2% and the forward extremity of said extension is engaged by a retractor 44 mounted on the pivot pin 32. Rotation of the retractor 44 occurs when inward movement of the adjacent extremity of the bolt extension 24 occurs.

Therefore, the dogging blade 2% is normally extended into the position shown in FIGS. 2 and 5 of the drawings by the action of the spring 38 but, when the bolt 18 is urged into the case 22 against the bias of the bolt spring 43, the extremity of the bolt extension 24 will engage and cause rotation of the blade retractor 44. The engagement of the blade retractor 44 upon the outer extremity of the extension 4d of the dogging blade 2% will cause the retraction of the dogging blade Ztl, for a purpose to be described in greater detail below.

The exterior knob 16 is mounted for rotation in an escutcheon plate 54) and has a half-round spindle 52 secured thereto and adapted to impinge upon the protruding extremities of the slide 28 and dogging blade 29 to cause retraction of the bolt 18 by urging the slide 28 forward in the latch case 22 and thus causing counterclockwise rotation of the retractor cam 34 to draw the bolt 18 into the latch case 22. A cylinder lock 54 is mounted in the exterior knob 15 and includes a cylinder lock housing 56 and plug 58 rotatable in said housing.

The plug 58, as best shown in FIGS. 2, 4-5 of the drawings, includes a keyway 65 which is adapted to receive the bit of a conventional key 64-, as best shown in FIG. 8 of the drawings. A key -64, when inserted in the 'keyway 60, will normally cause the tumblers, not shown, to release the plug 53 to permit relative rotation between 13 the plug 58 and the housing 56 and to release a normally locked locking mechanism, not shown, which prevents rotation of the exterior knob 16 and the associated exteriorhalfs'ound spindle 52, thus preventing release of the bolt did from an associated strike, not shown.

The interior knob id is mounted for rotation in an escutcheon plate as and is secured to an interior haltround spindle 7d, the interior half-round spindle 7t} and the exterior half-round spindle 52 being located in overlying relationship with each other and extending through a corresponding opening '72 in the latch case 22 to engage the adjacent extremities of the slide 28 and the dogging blade 263, as best shown in F1 6 of the drawings.

The interior knob 14- incorporates an opening 74 in its ront face for the reception of the actuator 76 of the lockout or blocking means of the invention. The lockout means Si) includes a yoke 32 which is slidably mounted in a corresponding slot in the cylinder lock plug 58. The yoke 82 has a recess 36, adapted for the reception of a ball detent 83 which is adapted to be urged through a bore S tl into the keyway of the plug 53 to obstruct the entry of the bit 62 of the key 64 into the keyway es and thus prevent release of the plug 58, and, consequently, to prevent release of the lock, not shown, associated therewith.

The ball detent 88 is urged into the keyway 69 of the plug 58 by biasing the yoke 82 outwardly to dislodge the ball detent 88 from the recess 86 and thus urge it into the keyway 65 as best shown in FIG. of the drawings. The forward extremity of the yoke 82 includes an indicator finger 2 which, as best shown in FIG. 2 of the drawings, is normally retracted in a corresponding opening in the plug 5% but is extended for visual perception when the lockout means is energized by outward mov ment of the yoke $2, as best shown in FIG. 5 of the drawings.

A compression spring M encompasses the indicator finger 9'2 and is interposed between the plug cover 95 and the adjacent extremity of the yoke S2, so that when the yoke 8-2 is released by the actuator '76, in a manner to be described in greater detail below, the yoke :32 will be urged into its inoperative position to locate the recess as in said yoke adjacent the ball detent S8 and permit the ball detent 88 to drop into said recess 86 and, once again, permit the usual key M to be inserted in the keyway 6d of the plug 58.

If management should desire to obtain entry into a room in which the blocking mechanism bil has been energized by a guest, in a manner to be described in greater detail below, a master key 96 is utilized, said key having a bit 93 incorporating an enlarged groove 159 which, as best shown in FIGS. 9-10 of the drawings, is adapted to bypass the ball detent 83 and thus permit complete entry of the bit 98 into the keyway es, thus permitting release of the plug 53 from the locking tumblers, not shown.

The actuator 76 for the lockout means or mechanism 8t} includes an elongated push rod 162 which, as best shown in FIGS. 2 and 5 of the drawings, has a threaded extremity 1 34 located in the interior knob 14 and mounting a push button 166 which is threadedly and adjustably engaged upon said threaded extremity The push button 106 incorporates an opening 1% permitting access to a key opening 11% in the end of the threaded extremity 104 of the push rod 162, for a purpose which will be described in greater detail below.

The push rod 102 has a cylindrical boss I112 formed thereupon intermediate its extremities and said cylindrical boss incorporates a plurality of detent dogs 114 which, as best shown in FIG. 2 of the drawings, are normally disposed to the left of the adjacent extremity of the dogging blade 2% by the action of a compression spring 116 interposed between the cylindrical boss 112 and a seat 113 provided on a portion of the lock, not shown. The righthand extremity 120 of the push rod W2 engages the lefthand or inner extremity of the yoke 82.

The enlarged, cylindrical boss 112 incorporates a slot 122 which, as best shown in FIGS. 2, 57 of the drawings, is adapted to receive a dog 124 formed on the exterior half-round spindle 52. The push rod M 2 cannot be shifted too far to the left, when the actuator '76 for the blocking or lockout mechanism is inoperative, since the head on the right-hand extremity 12d of the push rod seats on the seat portion idd, as best shown in FIG. 2 of the drawings. In addition, the dog 124 serves as a guide in the slot 122 to properly orient the dogging lugs 114 with respect to the dogging blade 2%.

A shorter slot 12% communicates with the slot 122 and has a right-hand extremity 13G engageable by the dog 124 on the exterior spindle 52. Therefore, the dogging lugs 114 on the cylindrical boss 112 of the push rod 1&2 and the dogging blade 2i? engageable therewith constitute first dogging means operative, in a manner to be described in greater detail below, to permit a guest to energize the lockout or blocking mechanism 86. The dog 124 on the exterior half-round spindle 52 and the shorter slot 128 constitute second dogging means operative only by the management through the use of a special key 132. The special key 132 has a bit 13 of substantially rectangular configuration and is receivable in the correspondingly shaped opening or bore 110 in the threaded inner extremity ltld of the push rod 102.

If a guest desires to prevent access to the room with which the lockset It is associated, he need merely depress the push button 166 in the opening 74 in the interior knob 14. This will cause the dogging lugs 114 on the cylindrical boss 11?. of the push rod 192 to be carried to the right, as viewed in FIG. 11 of the drawings, to engage the adjacent extremity of the dogging blade 2% and thus the first dogging means constituted by said blade and said lugs serves to maintain the right-hand extremity 12d of the push rod 162, as best shown in FIG. 5 of the drawings, in a position in which the yoke 32 maintains the detent ball 88 in the keyway 60 of the key plug 58 to prevent the usual key 64 from being fully inserted in the keyway 60. Thus, a guest can prevent another person from entering the room by energization of the cylinder lock 54.

Of course, if the management should desire access to the room the master key 96 is utilized. Insertion of the bit $8 of the master key 96 in the keyway 6d of the plug 58 will register the enlarged groove 100 in the bit 98 of said key with the detent ball 88 and permit the same to be bypassed. When this occurs the tumblers, not shown, locking the plug 58 to the housing 56 of the cylinder lock 54 will be released from the plug 58 permitting relative rotation between said plug and said housing and unlocking of the lock, not shown, to permit consequent rotation of the exterior half-round spindle 52 by the knob 16.

Rotation of the half-round spindle 52 will cause the dogging blade 26 to be released from. operative engagement with the dogging lugs 1014 because the slide 2t} and the dogging blade 29 will be urged inwardly into the latch case 22 by the action of the exterior half-round spindle 52. During this action the released push rod 162 will be urged to the left by the action of the compression spring 116 to project the push button res through the opening '74. Simultaneously, the compression spring 94 will urge the yoke '82 to the left and draw the indicator finger $2 into the plug 58 in the exterior knob 16.

If the occupant of a room should set the lockout mechanism by depressing the'push button 1% in the above described manner and then rotate the interior knob 14 in order to withdraw the bolt 18 so that he may leave the room, the lockout mechanism 869 will automatically be released. Such release is accomplishedbecause the interior half-round spindle 7G is rotated by rotation of the interior knob 14 whichcauses both the dogging blade 20 and the slide 28 to be urged into the latch case 22 to free the dogging blade 20 from operative engagement with the dogging lugs 114. Of course, when this occurs, the compression spring'llo will bias the push rod 14%2 to the left,

as viewed in FIG. 2 of the drawings, and move the doging lugs 11.4 out of engagement with the dogging blade 2%. Therefore, the yoke 32 will be urged to the left by the action of the compression spring 94 and the lockout mechanism 80 rendered inoperative. Therefore, it is impossible for a guest to maintain the lockout mechanism so in operative condition after he has left the room and thus he cannot look himself or personnel of the hotel or motel out of the room either inadvertently or deliberately.

If the management should desire, for any reason whatsoever, to prevent a guest from reentering the room with which the lock set is associated, the rectangular bit 134 of the special key 132 is inserted in the correspondingly shaped key opening 110 in the threaded extremity 104 of the elongated push rod N2. By turning the key in a clockwise direction While simultaneously depressing the push rod 102, the dogging lug 124- on the exterior half round spindle 52 is engaged upon the adjacent extremity 130 of the shorter slot 128 in the cylindrical boss 112 on the push rod 102. Therefore, the yoke 82 is once again urged to the right, as viewed in FIG. 5 of the drawings, to project the detent ball 88 into the keyway at} of the plug 58. Of course, the indicator 92 is projected outwardly to present a visual indication that the lookout mechanism 80 has been actuated.

After energization of the lookout mechanism in the above described manner, the door 12 can be closed and and the bolt r18 depressed against its associated strike, not shown, without releasing the push rod 1&2. from the operative position shown in FIG. 5 of the drawings wherein the lockout mechanism 80 is maintained in operative condition. This is due to the fact that even though the dogging blade 20 and the associated slide 28 are drawn into the latch case 22 by the depressing of the bolt 18, the push rod 102 is maintained in dogged condition by the second dogging means constituted by the shorter slot 128 and the associated dog 124 on the half-round spindle 52. Therefore, management can energize the lockout mechanism 8t and can leave the room without releasing the lockout mechanism 80.

Once the lockout mechanism 8% has been energized in the above described manner, the master key )6 must be utilized in order that the detent ball 88 may be bypassed by the enlarged groove 1W provided in the key bit 8. Of course, insertion of the key bit 98 of the key 96 will cause the groove 11% in said bit to bypass the detent ball 88 and permit relative rotation between the plug 58 and the housing 56 of the cylinder lock 54. When this occurs the exterior half-round spindle 52 is rotated to Withdraw the bolt 18.

However, in order to inactivate the lockout mechanism, it is necessary to insert the rectangular bit 1-34 of the special key 132 in the correspondingly shaped opening 1% of the elongated push rod 192 and turn the key 132 to release the dog 24 from operative engagement with the right-hand extremity of the shorter slot 128.

A lockout mechanism constructed in accordance with the teachings of the invention is thus characterized by its simplicity of construction, ease of operation and relatively low cost of manufacture. The lockout mech anism may be utilized by a guest during his occupancy of a room to prevent undesirable access of those personnel having regular keys. However, management can utilize the lockout mechanism to prevent a guest from obtaining access to a room if such access is not desired for any reason.

The provision of the first dogging means constituted by the dogging blade 26 and the dogging lugs 114-, and the second dogging means constituted by the dogging lug 124 on the exterior half-round spindle 52 and the shorter slot 12%, facilitates the actuation of the lockout mechanism 80 in the above described alternative man- I claim:

1. In a lock set for a door, the combination of: an exterior spindle; an exterior knob mounted on said exterior spindle; an interior spindle; an interior knob mounted on said interior spindle; a cylinder lock mounted in said exterior knob and constituted by a cylinder lock housing and a plug mounted for rotation in said housing, said plug including a keyway and a lateral opening communicating with said keyway; lockout means for preventing utilization of said lock, said lockout means including an axially shiftable operator mounted in said plug and an obstruction engageable by said operator and located in said lateral opening whereby axial movement of said operator in a first direct-ion will cause said obstruction to be projected through said opening into said keyway; an actuator operative to axially move said operator in said first direction, said actuator having a portion engageable from said interior knob whereby said axially shiftable operator may be moved from said interior knob through said actuator to obstruct said keyway, said actuator including a push rod; first dogging means for engaging said push rod to maintain said push rod in a position in which said push rod will maintain said operator and said obstruction in keyway blocking positions; and second dogging means having cooperating portions, respectively, on said push rod and on one of said exterior and interior spindles, said portions of said second dogging means being normally disengaged to perrnit axial movement of said actuator in a second direction opposite to said first direction, said push rod being rotatable to effect engagement of said portions of said dogging means to prevent movement of said actuator in said second direction.

2. In a lock set for a door, the combination of: an exterior knob; an interior knob; a bolt openatively connected to said exterior and interior knobs; a cylinder lock mounted in said exterior knob including a housing and a plug rotatable therein, said plug incorporating a keyway and a lateral bore communicating with said keyway; lockout means mounted in said cylinder lock and including an axially movable operator and a laterally movable obstruction in said bore adapted to prevent insertion of a key in said keyway beyond a predetermined point; an actuator connected to said axially shiftable operator and operable from said interior knob to axially shift said axially shiftable operator in a first direction in said lock to project said obstruction into said keyway; a first dog engageable with said actuator to maintain said obstruction in operation until said door is opened; and a second dog having coperating portions normally disengaged to permit axial movement of said operator in a second direction opposite to said first direction, said actuator being rotatable to effect engagement of said portions of said second dog to prevent movement of said actuator in said second direction, there by preventing release of said actuator when said door is opened from the interior thereof.

3. In a lock set for a door, the combination of: an exterior knob; an interior knob; a bolt operatively connected to said exterior and interior knobs; a cyhnder lock mounted in said exterior knob including a housing and a plug rotatable therein, said plug incorporating a keyway and a lateral bore communicating with said keyway; lockout means mounted in said cylinder lock and including an axially movable operator and a laterally movable obstruction in said bore adapted to prevent insertion of a key in said keyway beyond a predetermined point; an actuator connected to said axially shiftable operator and operable from said interior knob to axially shift said axially shifta-ble operator in a first direction in said lock to project said obstruction into said keyway; a first dog engageable with said actuator to maintain said obstruction in operation until said door is opened; a second dog having cooperating portions normally disengaged to permit axial movement of said operator in a second direction opposite to said first disan ers rection, said actuator being rotatable to eifect engagemerit of said portions of said second dog to prevent movement of said actuator in said second direction thereby preventing release of said actuator when said door is opened from the interior thereof; and an indicator op,- eratively connected to said axially shiftable operator to indicate the operation of said lockout means.

4. in a lock set having a locking mechanism, the combination of: an exterior knob; an exterior spindle connected to said exterior knob; an interior knob; an interior spindle connected to said interior knob; a cylinder lock mounted in said exterior knob and including a housing and a plug rotatable in said housing for unlocking the locking mechanism of the lockset, said plug including a keyway for receiving a key to rotate said plug; lockout means operative to obstruct said keyway and including a push rod, an actuating element located in said interior knob and operative to axially move said push rod to render said lockout means operative, and bias means tending to axially move said push rod to render said lockout means inoperative; a latching mechanism; first dogging means having cooperating portions on said latching mechanism and on said push rod, respectively, said portions being engageable, upon operation of said lockout means, to overcome the bias of said bias means and maintain said push rod in a position rendering said lockout means operative; and second dogging means having cooperating portions, respectively, on said push rod and on one of said exterior and interior spindles, said portions of said second dogging means being normally discu aged to permit said bias means to axially move said push rod, said push rod being rotatable to effect engagement of said portions of said second dogging means to prevent axial movement of said push rod by said bias means.

5. in a lockset having a locking mechanism, the combinadon of: an exterior knob; an exterior spindle con nected to said exterior knob; an interior knob; an interior spindle connected to said interior knob; a cylinder lock mounted in said exterior knob and including a housing and a plug rotatable in said housing for unlocking the locking mechanism of the lockset, said plug including a keyway for receiving a key to rotate said plug; lockout means operative to obstruct said keyway and including a push rod, an actuating element located in said interior knob and operative to axially move said push rod to render said lockout means operative, and bias means tending to axially move said push rod to render said lockout means inoperative; a latching mechanism including a latch bolt, said latching mechanism being actuable by said exterior and interior spindles for retraction of said latch bolt; first dogging means having cooperating portions on said latching mechanism and on said push rod, respectively, said portions being engageable, upon operation of said lockout means, to overcome the bias of said bias means and maintain said push rod in a position rendering said lockout means operative, said portions of said first dogging means being disengaged upon retraction of said latch bolt; and second dogging means having cooperating portions, respectively, on said push rod and on one of said exterior and interior spindles, said portions of said second dogging means being normally disengaged to permit said bias means to axially move said push rod, said push rod being rotatable to efiect engagement of said portions of said second dogging means to prevent axial movement of said push rod by said bias means.

6. In a lockset having a locking mechanism, the combination of: an exterior knob; an exterior spindle connected to said exterior knob; an interior knob; an interior spindle connected to said interior knob; a cylinder lock mounted in said exterior knob and including a housing and a plug rotatable in said housing for unlocking the locking mechanism of the lockset, said plug including a keyway for receiving a key to rotate said plug; lockout means operative to obstruct said keyway and including a push rod, an actuating element located in said interior knob and operative to axially move said push rod to render said lockout means operative, bias means tending to axially move said push rod to render said lockout means inoperative, an obstructing element for obstructing said keyway, and carried in and rotatable with said plug, and an indicator axially shiitable upon operation of sa d lockout means to project from said exterior knob; a latching mechanism; first dogging means having cooperating portions on said latching mechanism and on said push rod, respectively, said portions being engageable, upon operation of said lockout means, to overcome the bias of said bias means and maintain said push rod in a pc on rendering said lockout means operative; and second dogging means having cooperating portions, respectively, on said push rod and on one of said exterior and interior spindles, sai portions of said second dogging means being normally disengaged to permit said. bias means to axially move said push rod, said push rod being rotatable to ei'fec't engagement of said portions of said second dogging means to prevent axial movement of said p sh rod by said bias means.

in a lockset having a locking mechanism, the combination of: an exterior knob; a spindle connected to said exterior knob; an interior knob; a spindle connected to said interior knob; a cylinder lock mounted in said exterior knob and including a housing and a plug rotatable in said housing for unlocking the locking mechanism of the lockset, said plug including a keyway for receiving a key to rotate said plug; lockout means including a blocking member laterally shiitable in said plug to a locking position for obstructing said keyway, an operating member axially shiitable outwardly to move said blocking member to said blocking position, and an actuator for said lockout means, said actuator including an actuating element located in said interior knob and a push rod extending between said actuating element and said operating member, said actuating element being operative to move said push rod to an outward position to axially shift said operating member outwardly for moving said blocking member to said blocking position; a latching mechanism including a latch bolt, said latching mechanism being actuable by the spindles of said exterior knob and said interior knob for retraction of said latch bolt; first dogging means having cooperating portions on said rod and on said latching mechanism, respectively, said portions being engageable, upon operation of said actuating element, to maintain said push rod in said outward position, said portions of said first dogging means being disengaged upon retraction of said latch bolt; and second dogging means having cooperating portions, respectively, on said push rod and on one of the spindles of said interior knob and said exterior knob, said portions of said second dogging means being normally disengaged to permit movement of said push rod toward and away from said outward position, said push rod being rotatable to engage said portions of said second dogging means and prevent movement of said push rod away from said outward position.

References Cited in the file of this patent UNITED STATES PATENTS 2,018,093 Schlage Oct. 22, 1935 2,087,554 Schoorel July 20, 1937 2,294,308 Larson Aug. 25, 1942 2,738,666 Tornoe Mar. 20, 1956 2,836,973 Schillizzi June 3, 1958 2,948,140 Etsten Aug. 9, 1960 

4. IN A LOCK SET HAVING A LOCKING MECHANISM, THE COMBINATION OF: AN EXTERIOR KNOB; AN EXTERIOR SPINDLE CONNECTED TO SAID EXTERIOR KNOB; AN INTERIOR KNOB; AN INTERIOR SPINDLE CONNECTED TO SAID INTERIOR KNOB; A CYLINDER LOCK MOUNTED IN SAID EXTERIOR KNOB AND INCLUDING A HOUSING AND A PLUG ROTATABLE IN SAID HOUSING FOR UNLOCKING THE LOCKING MECHANISM OF THE LOCKSET, SAID PLUG INCLUDING A KEYWAY FOR RECEIVING A KEY TO ROTATE SAID PLUG; LOCKOUT MEANS OPERATIVE TO OBSTRUCT SAID KEYWAY AND INCLUDING A PUSH ROD, AN ACTUATING ELEMENT LOCATED IN SAID INTERIOR KNOB AND OPERATIVE TO AXIALLY MOVE SAID PUSH ROD TO RENDER SAID LOCKOUT MEANS OPERATIVE, AND BIAS MEANS TENDING TO AXIALLY MOVE SAID PUSH ROD TO RENDER SAID LOCKOUT MEANS INOPERATIVE; A LATCHING MECHANISM; FIRST DOGGING MEANS HAVING COOPERATING PORTIONS ON SAID LATCHING MECHANISM AND ON SAID PUSH ROD, RESPECTIVELY, SAID PORTIONS BEING ENGAGEABLE, UPON OPERATION OF SAID LOCKOUT MEANS, TO OVERCOME THE BIAS OF SAID BIAS MEANS AND MAINTAIN SAID PUSH ROD IN A POSITION RENDERING SAID LOCKOUT MEANS OPERATIVE; AND SECOND DOGGING MEANS HAVING COOPERATING PORTIONS, RESPECTIVELY, ON SAID PUSH ROD AND ON ONE OF SAID EXTERIOR AND INTERIOR SPINDLES, SAID PORTIONS OF SAID SECOND DOGGING MEANS BEING NORMALLY DISENGAGED TO PERMIT SAID BIAS MEANS TO AXIALLY MOVE SAID PUSH ROD, SAID PUSH ROD BEING ROTATABLE TO EFFECT ENGAGEMENT OF SAID PORTIONS OF SAID SECOND DOGGING MEANS TO PREVENT AXIAL MOVEMENT OF SAID PUSH ROD BY SAID BIAS MEANS. 